Interactions of laminin with the amyloid ß peptide: Implications for Alzheimer's disease

Extensive neuronal cell loss is observed in Alzheimer's disease. Laminin immunoreactivity colocalizes with senile plaques, the characteristic extracellular histopathological lesions of Alzheimer brain, which consist of the amyloid ß (Aß) peptide polymerized into amyloid fibrils. These lesions have neurotoxic effects and have been proposed to be a main cause of neurodegeneration. In order to understand the pathological significance of the interaction between laminin and amyloid, we investigated the effect of laminin on amyloid structure and toxicity. We found that laminin interacts with the Aß1-40 peptide, blocking fibril formation and even inducing depolymerization of preformed fibrils. Protofilaments known to be intermediate species of Aß fibril formation were also detected as intermediate species of laminin-induced Aß fibril depolymerization. Moreover, laminin-amyloid interactions inhibited the toxic effects on rat primary hippocampal neurons. As a whole, our results indicate a putative anti-amyloidogenic role of laminin which may be of biological and therapeutic interest for controlling amyloidosis, such as those observed in cerebral angiopathy and Alzheimer's disease.

von Willebrand factor antigen levels in plasma of patients with malignant breast disease

von Willebrand factor (vWF) is a protein that mediates platelet adherence to the subendothelium during primary hemostasis. High plasma vWF concentrations have been reported in patients with various types of cancer, such as head and neck, laryngeal and prostatic cancer, probably representing an acute phase reactant. In the present study we determined the plasma levels of vWF antigen (vWF:Ag) by quantitative immunoelectrophoresis in 128 female patients with breast cancer as well as in 47 women with benign breast disease and in 27 healthy female controls. The levels of vWF:Ag were 170.7 ± 78 U/dl in patients with cancer, 148.4 ± 59 U/dl in patients with benign disease and 130.6 ± 45 U/dl in controls (P<0.005). We also detected a significant increase in the levels of vWF:Ag (P<0.0001) in patients with advanced stages of the disease (stage IV = 263.3 ± 113 U/dl, stage IIIB = 194.0 ± 44 U/dl) as compared to those with earlier stages of the disease (stage I = 155.3 ± 65 U/dl, stage IIA = 146.9 ± 75 U/dl). In conclusion, vWF levels were increased in plasma of patients with malignant breast disease, and these levels correlated with tumor progression.

Development according to pubertal stage in Brazilian children and adolescents with short-term diabetes

The anthropometric status and metabolic control of 51 recently diagnosed Brazilian schoolchildren with type 1 diabetes (DM1), during the first 5 years of the disease, were compared with those of normal children (60 girls and 132 boys) belonging to the same environmental condition and pubertal stage. Metabolic control was evaluated on the basis of fasting plasma glucose (FPG) and HbA1c levels. The criteria of the National Center for Health Statistics were used for anthropometric evaluation. FPG (205 ± 51 mg/dl for girls vs 200 ± 34 mg/dl for boys) and % above upper normal limit of median HbA1c (1.8% for girls vs 2.5% for boys with diabetes) were not significantly different during follow-up. The Z-score of the last height evaluation was lower in the girls' group (-0.14 vs -0.53, P<0.05). By forward stepwise analysis, the Z-score of the initial height was statistically significant as a determinant factor for height at the end of the study in both girls and boys with DM1. The Z-score of weight at last evaluation was not different from that at diagnosis in either sex. However, analysis according to pubertal stage showed a tendency to a weight increase in the girls. The weight recovery and height loss in girls with DM1 follows the trend of the normal Brazilian population.

Effect of meconium ileus on the clinical prognosis of patients with cystic fibrosis

The objective of the present study was to determine the possible prognostic factors which may explain the difference in the survival of patients with cystic fibrosis (CF) with and without meconium ileus. Over a period of 20 years, 127 patients with CF, whose diagnosis was confirmed by typical clinical characteristics and altered sweat chloride levels, were studied retrospectively. The patients were divided into two groups: group 1 consisted of patients who presented CF and meconium ileus (N = 9), and group 2 consisted of patients with CF without meconium ileus (N = 118). The characteristics studied were based on data obtained upon admission of the patients using a specific protocol. Demographic, clinical, nutritional and laboratory data were obtained. The genotype was determined in 106 patients by PCR. Survival was analyzed using the Kaplan-Meier method. The median follow-up period was 44 months. A statistically significant difference was observed between the groups studied regarding the following variables: age at diagnosis and weight and height z scores. The presence of meconium ileus was associated with an earlier diagnosis; these patients had greater deficits in height and weight at the time of diagnosis and at the end of the study. The estimated probability of survival for patients with CF without meconium ileus was 62 ± 14% and for those with meconium ileus 32 ± 18%. Patients with CF and meconium ileus presented a poor nutritional status at diagnosis and a lower survival rate compared to the general CF population.

Six years of treatment with the HELP system of a patient with familial hypercholesterolemia

The purpose of the present report is to demonstrate the long-term efficacy and safety of heparin-induced extracorporeal lipoprotein precipitation (HELP) of LDL-c and fibrinogen in the management of familial hypercholesterolemia. From June 1992 to June 1998 a 22-year-old young male patient with familial hypercholesterolemia (double heterozygote for C660X and S305C) resistant to medication and diet and with symptomatic coronary artery disease (angina) was treated weekly with 90-min sessions of the HELP system. The patient had also been previously submitted to right coronary artery angioplasty. The efficacy of the method was evaluated by comparing the reduction of total cholesterol, LDL-c and fibrinogen before and after the sessions and before and after initiation of the study (data are reported as averages for each year). During the study, angina episodes disappeared and there were no detectable adverse effects of the treatment. Total cholesterol (TC), fibrinogen, and LDL-c decreased significantly after each session by 59.6, 66.1 and 64%, respectively. HDL-c showed a nonsignificant reduction of 20.4%. Comparative mean values pre- and post-treatment values in the study showed significant differences: TC (488 vs 188 mg/dl), LDL-c (416.4 vs 145 mg/dl), and fibrinogen (144.2 vs 57.4 mg/dl). There was no significant change in HDL-c level: 29.4 vs 23 mg/dl. These data show that the HELP system, even for a long period of time, is a safe and efficient mode of treatment of familial hypercholesterolemia and is associated with disappearance of angina symptoms.

Nitric oxide, cholesterol oxides and endothelium-dependent vasodilation in plasma of patients with essential hypertension

The objective of the present study was to identify disturbances of nitric oxide radical (·NO) metabolism and the formation of cholesterol oxidation products in human essential hypertension. The concentrations of·NO derivatives (nitrite, nitrate, S-nitrosothiols and nitrotyrosine), water and lipid-soluble antioxidants and cholesterol oxides were measured in plasma of 11 patients with mild essential hypertension (H: 57.8 ± 9.7 years; blood pressure, 148.3 ± 24.8/90.8 ± 10.2 mmHg) and in 11 healthy subjects (N: 48.4 ± 7.0 years; blood pressure, 119.4 ± 9.4/75.0 ± 8.0 mmHg).Nitrite, nitrate and S-nitrosothiols were measured by chemiluminescence and nitrotyrosine was determined by ELISA. Antioxidants were determined by reverse-phase HPLC and cholesterol oxides by gas chromatography. Hypertensive patients had reduced endothelium-dependent vasodilation in response to reactive hyperemia (H: 9.3 and N: 15.1% increase of diameter 90 s after hyperemia), and lower levels of ascorbate (H: 29.2 ± 26.0, N: 54.2 ± 24.9 µM), urate (H: 108.5 ± 18.9, N: 156.4 ± 26.3 µM), ß-carotene (H: 1.1 ± 0.8, N: 2.5 ± 1.2 nmol/mg cholesterol), and lycopene (H: 0.4 ± 0.2, N: 0.7 ± 0.2 nmol/mg cholesterol), in plasma, compared to normotensive subjects. The content of 7-ketocholesterol, 5alpha-cholestane-3ß,5,6ß-triol and 5,6alpha-epoxy-5alpha-cholestan-3alpha-ol in LDL, and the concentration of endothelin-1 (H: 0.9 ± 0.2, N: 0.7 ± 0.1 ng/ml) in plasma were increased in hypertensive patients. No differences were found for ·NO derivatives between groups. These data suggest that an increase in cholesterol oxidation is associated with endothelium dysfunction in essential hypertension and oxidative stress, although ·NO metabolite levels in plasma are not modified in the presence of elevated cholesterol oxides.

Dietary fiber, energy intake and nutritional status during the treatment of children with chronic constipation

The present prospective study was carried out to determine dietary fiber and energy intake and nutritional status of children during the treatment of chronic constipation. Twenty-five patients aged 2 to 12 years with chronic constipation were submitted to clinical evaluation, assessment of dietary patterns, and anthropometry before and after 45 and 90 days of treatment. The treatment of chronic constipation included rectal disimpaction, ingestion of mineral oil and diet therapy. The standardized diet prescribed consisted of regular food without a fiber supplement and met the nutrient requirements according to the recommended daily allowance. The fiber content was 9.0 to 11.9 g for patients aged less than 6 years and 12.0 to 18.0 g for patients older than 6 years. Sixteen patients completed the 90-day follow-up and all presented clinical improvement. The anthropometric variables did not change, except midarm circumference and triceps skinfold thickness which were significantly increased. Statistically significant increases were also found in percent calorie intake adequacy in terms of recommended daily allowance (55.5 to 76.5% on day 45 and to 68.5% on day 90; P = 0.047). Percent adequacy of minimum recommended daily intake of dietary fiber (age + 5 g) increased during treatment (from 46.8 to 52.8% on day 45 and to 56.3% on day 90; P = 0.009). Food and dietary fiber intake and triceps skinfold thickness increased during follow-up. We conclude that the therapeutic program provided a good clinical outcome.

Prevalence of Y chromosome deletions in a Brazilian population of nonobstructive azoospermic and severely oligozoospermic men

We determined the prevalence of Y chromosome deletions in a population of 60 Brazilian nonobstructive azoospermic and severely oligozoospermic men. PCR-based screening of microdeletions was performed on lymphocyte DNA for the presence of 14 sequence-tagged sites (STS) located in the azoospermic factor (AZF) on the Yq chromosome. All STS were amplified efficiently in samples from 12 fertile men tested, but failed to be amplified in samples from fertile women, indicating the specificity of PCR conditions for Yq screening. Overall, 4 of the 60 infertile patients tested (6.7%) exhibited deletion of the Y chromosome, 2 of them being severely oligozoospermic patients (P10 and P32) and 2 azoospermic men (patients P47 and P57). Patients P47 and P57 presented larger deletions in the AZFa, AZFb and AZFc subregions, with apparent loss of Yq material evidenced by karyotype analysis. Patients P10 and P32 presented deletions confined to the AZFc region, involving the DAZ locus. Male relatives of patients P10 and P32 had no Y chromosome deletions and presented a normal karyotype, suggesting a de novo status of the deletions found. Our data add to the growing literature showing that microdeletions of the Y chromosome can be the cause of male idiopathic infertility.

Effect of an aqueous extract of Phaseolus vulgaris on the properties of tail tendon collagen of rats with streptozotocin-induced diabetes

Changes in the structural and functional properties of collagen caused by advanced glycation might be of importance for the etiology of late complications in diabetes. The present study was undertaken to investigate the influence of oral administration of aqueous pod extract (200 mg/kg body weight) of Phaseolus vulgaris, an indigenous plant used in Ayurvedic Medicine in India, on collagen content and characteristics in the tail tendon of streptozotocin-diabetic rats. In diabetic rats, collagen content (117.01 ± 6.84 mg/100 mg tissue) as well as its degree of cross-linking was increased, as shown by increased extent of glycation (21.70 ± 0.90 µg glucose/mg collagen), collagen-linked fluorescence (52.8 ± 3.0 AU/µmol hydroxyproline), shrinkage temperature (71.50 ± 2.50ºC) and decreased acid (1.878 ± 0.062 mg hydroxyproline/100 mg tissue) and pepsin solubility (1.77 ± 0.080 mg hydroxyproline/100 mg tissue). The alpha/ß ratio of acid- (1.69) and pepsin-soluble (2.00) collagen was significantly decreased in streptozotocin-diabetic rats. Administration of P. vulgaris for 45 days to streptozotocin-diabetic rats significantly reduced the accumulation and cross-linking of collagen. The effect of P. vulgaris was compared with that of glibenclamide, a reference drug administered to streptozotocin-diabetic rats at the dose of 600 µg/kg body weight for 45 days by gavage. The effects of P. vulgaris (collagen content, 64.18 ± 1.97; extent of glycation, 12.00 ± 0.53; collagen-linked fluorescence, 33.6 ± 1.9; shrinkage temperature, 57.0 ± 1.0; extent of cross-linking - acid-soluble collagen, 2.572 ± 0.080, and pepsin-soluble collagen, 2.28 ± 0.112) were comparable with those of glibenclamide (collagen content, 71.5 ± 2.04; extent of glycation, 13.00 ± 0.60; collagen-linked fluorescence, 38.9 ± 2.0; shrinkage temperature, 59.0 ± 1.5; extent of cross-linking - acid-soluble collagen, 2.463 ± 0.078, and pepsin-soluble collagen, 2.17 ± 0.104). In conclusion, administration of P. vulgaris pods had a positive influence on the content of collagen and its properties in streptozotocin-diabetic rats.

Prevalence of celiac disease in Brazilian children of short stature

The aim of the present study was to determine the prevalence of celiac disease in children of short stature and to assess whether some of the routine laboratory examinations performed to determine the cause of short stature could suggest the presence of celiac disease. A total of 106 children of short stature and no gastrointestinal symptoms were studied. An extensive endocrine work-up had been negative for all of them and an additional investigation was performed by measuring the concentration of antiendomysial antibody. Patients who were positive for antiendomysial antibody ( > or = 1:10) or who exhibited IgA deficiency (less than 5 mg/dl) were referred for an endoscopic intestinal biopsy. We detected a pathological titer of antiendomysial IgA in six of these patients. Five of them showed histological abnormalities compatible with celiac disease and one had normal histology and was considered to have potential celiac disease. The prevalence of celiac disease in the population studied was 4.7% (with another 0.9% of the subjects being considered to have potential celiac disease). The children with celiac disease did not differ in any of the parameters tested when compared to those without celiac disease, though they showed an improvement in growth velocity after treatment with a gluten-free diet. We conclude that it is important to test all children with short stature for celiac disease by measuring antiendomysial IgA.

Interferon-alpha receptor 1 mRNA expression in peripheral blood mononuclear cells is associated with response to interferon-alpha therapy of patients with chronic hepatitis C

Interferon (IFN)-alpha receptor mRNA expression in liver of patients with chronic hepatitis C has been shown to be a response to IFN-alpha therapy. The objective of the present study was to determine whether the expression of mRNA for subunit 1 of the IFN-alpha receptor (IFNAR1) in peripheral blood mononuclear cells (PBMC) is associated with the response to IFN-alpha in patients with chronic hepatitis C. Thirty patients with positive anti-HCV and HCV-RNA, and abnormal levels of alanine aminotransferase in serum were selected and treated with IFN-alpha2b for one year. Those with HBV or HIV infection, or using alcohol were not included. Thirteen discontinued the treatment and were not evaluated. The IFN-alpha response was monitored on the basis of alanine aminotransferase level and positivity for HCV-RNA in serum. IFNAR1-mRNA expression in PBMC was measured by reverse transcription-polymerase chain reaction before and during the first three months of therapy. The results are reported as IFNAR1-mRNA/ß-actin-mRNA ratio (mean ± SD). Before treatment, responder patients had significantly higher IFNAR1-mRNA expression in PBMC (0.67 ± 0.15; N = 5; P < 0.05) compared to non-responders (0.35 ± 0.17; N = 12) and controls (0.30 ± 0.16; N = 9). Moreover, IFNAR1-mRNA levels were significantly reduced after 3 months of treatment in responders, whereas there were no differences in IFNAR1 expression in non-responders during IFN-alpha therapy. Basal IFNAR1-mRNA expression was not correlated with the serum level of alanine and aspartate aminotransferases or the presence of cirrhosis. The present results suggest that IFNAR1-mRNA expression in PBMC is associated with IFN-alpha response to hepatitis C and may be useful for monitoring therapy in patients with chronic hepatitis C.

Brazilian version of the Berg balance scale

The purpose of the present study was to translate and adapt the Berg balance scale, an instrument for functional balance assessment, to Brazilian-Portuguese and to determine the reliability of scores obtained with the Brazilian adaptation. Two persons proficient in English independently translated the original scale into Brazilian-Portuguese and a consensus version was generated. Two translators performed a back translation. Discrepancies were discussed and solved by a panel. Forty patients older than 65 years and 40 therapists were included in the cultural adaptation phase. If more than 15% of therapists or patients reported difficulty in understanding an item, that item was reformulated and reapplied. The final Brazilian version was then tested on 36 elderly patients (over age 65). The average age was 72 years. Reliability of the measure was assessed twice by one physical therapist (1-week interval between assessments) and once by one independent physical therapist. Descriptive analysis was used to characterize the patients. The intraclass correlation coefficient (ICC) and Pearson's correlation coefficient were computed to assess intra- and interobserver reliability. Six questions were modified during the translation stage and cultural adaptation phase. The ICC for intra- and interobserver reliability was 0.99 (P < 0.001) and 0.98 (P < 0.001), respectively. The Pearson correlation coefficient for intra- and interobserver reliability was 0.98 (P < 0.001) and 0.97 (P < 0.001), respectively. We conclude that the Brazilian version of the Berg balance scale is a reliable instrument to be used in balance assessment of elderly Brazilian patients.

Morphological and functional alterations of the intestine of rats with iron-deficiency anemia

The present study was designed to assess the intestinal absorption of D-xylose and jejunal morphometry in rats with iron-deficiency anemia. Male Wistar rats were randomly divided into a control group (diet containing 50 mg Fe/kg, N = 12) and an anemic group (diet containing <5 mg Fe/kg, N = 12). The animals were housed in individual metabolic cages and deionized water and diet were provided ad libitum for 6 weeks. Hemoglobin and hematocrit were determined at 0, 2, 4, and 6 weeks. At the end of the study the rats were submitted to a D-xylose absorption test (50 mg/100 g body weight) and sacrificed and a jejunal specimen was obtained for morphometric study. At the end of the study the hemoglobin and hematocrit of the anemic rats (8.7 ± 0.9 g/dl and 34.1 ± 2.9%, respectively) were significantly (P < 0.05) lower than those of the controls (13.9 ± 1.4 g/dl and 47.1 ± 1.5%, respectively). There was no statistical difference in D-xylose absorption between the anemic (46.5 ± 7.4%) and control (43.4 ± 9.0%) groups. The anemic animals presented statistically greater villus height (445.3 ± 36.8 µm), mucosal thickness (614.3 ± 56.3 µm) and epithelial surface (5063.0 ± 658.6 µm) than control (371.8 ± 34.3, 526.7 ± 62.3 and 4401.2 ± 704.4 µm, respectively; P < 0.05). The increase in jejunum villus height, mucosal thickness and epithelial surface in rats with iron-deficiency anemia suggests a compensatory intestinal mechanism to increase intestinal iron absorption.

Laminin concentration in ascites of patients with hepatic cirrhosis and peritoneal carcinomatosis

Laminin levels in ascitic fluid have been proposed as a marker for neoplastic ascites. We compared the concentration of laminin in serum and in ascitic fluid from patients with hepatic cirrhosis and peritoneal carcinomatosis and assessed the diagnostic value of serum laminin levels in differentiating neoplastic from benign ascites. Laminin concentrations were determined by ELISA with antibodies against laminin extracted from the human placenta, in patients with ascites due to peritoneal carcinomatosis (N = 20) and hepatic cirrhosis (N = 33). Patients with infected or hemorrhagic ascites were excluded. The receiver operating characteristic curve was used to determine the sensitivity and specificity of serum laminin for the diagnosis of neoplastic ascites. When compared to the group with cirrhosis, the carcinomatosis group presented significantly higher mean laminin levels in serum (3.3 ± 0.5 vs 2.1 ± 0.4 µg/ml, mean ± SD, P < 0.05) and ascites (2.8 ± 0.5 vs 1.6 ± 0.4 µg/ml, P < 0.05). Although laminin concentration was higher in serum than in ascites, the laminin serum/ascites ratio and serum-ascites gradient did not differ between the studied groups. A significant correlation (r = 0.93, P < 0.0001) was observed between the serum and ascites laminin values. Serum laminin levels >2.25 µg/ml showed 100% sensitivity and 73% specificity for the diagnosis of neoplastic ascites. Serum concentration seems to be the main determinant of laminin levels in ascitic fluid and its values can be used as a diagnostic parameter in the study of neoplastic ascites.

Short-lasting systemic and regional benefits of early crystalloid infusion after intravenous inoculation of dogs with live Escherichia coli

We investigated the systemic and regional hemodynamic effects of early crystalloid infusion in an experimental model of septic shock induced by intravenous inoculation with live Escherichia coli. Anesthetized dogs received an intravenous infusion of 1.2 x 10(10) cfu/kg live E. coli in 30 min. After 30 min of observation, they were randomized to controls (no fluids; N = 7), or fluid resuscitation with lactated Ringer's solution, 16 ml/kg (N = 7) or 32 ml/kg (N = 7) over 30 min and followed for 120 min. Cardiac index, portal blood flow, mean arterial pressure, systemic and regional oxygen-derived variables, blood lactate, and gastric PCO2 were assessed. Rapid and progressive cardiovascular deterioration with reduction in cardiac output, mean arterial pressure and portal blood flow (~50, ~25 and ~70%, respectively) was induced by the live bacteria challenge. Systemic and regional territories showed significant increases in oxygen extraction and in lactate levels. Significant increases in venous-arterial (~9.6 mmHg), portal-arterial (~12.1 mmHg) and gastric mucosal-arterial (~18.4 mmHg) PCO2 gradients were also observed. Early fluid replacement, especially with 32 ml/kg volumes of crystalloids, promoted only partial and transient benefits such as increases of ~76% in cardiac index, of ~50% in portal vein blood flow and decreases in venous-arterial, portal-arterial, gastric mucosal-arterial PCO2 gradients (7.2 ± 1.0, 7.2 ± 1.3 and 9.7 ± 2.5 mmHg, respectively). The fluid infusion promoted only modest and transient benefits, unable to restore the systemic and regional perfusional and metabolic changes in this hypodynamic septic shock model.